Hi

Jee main 2021 is conducted in 4 sessions

• February session
• March session
• April session
• May session

JEE Main is conducted for 2 papers

• Jee main paper -1 ( for Be/ B. Tech)
• Jee main paper -2 ( for B. Arch/B. Planning)

Now,

You are confusing session with paper . If you have improved your percentile in 2nd session i. e March session then you need to enter your percentile obtained by you in March session as the best score/ percentile out of all the four attempts is considered for admission process.

You haven't mentioned whether you are asking about our rank predictor or college predictor but in the section where it is asking for percentile obtained in paper 1 ,

you can definitely  enter your improved percentile obtained by you in your second session i. e March session or can even enter percentile obtained by you in February season and get the corresponding results.

As,

You have not mentioned whether you are asking about college or rank predictor I am giving you below the link for both

Rank predictor :-

College predictor :-

Thank you